1,721,266 research outputs found
I primi passi dell'igiene industriale e della tossicologia occupazionale presso la Clinica del Lavoro di Milano sotto la guida di Luigi Devoto
Full text linkINTRODUCTION:
The Clinica del Lavoro, the first clinic for occupational diseases of the world, was inaugurated in Milan on 20 March 1910; its first director was Luigi Devoto, who was in charge until 1935. The purpose of this work is to review the activities of industrial hygiene and toxicology carried out at the Clinica del Lavoro under the guidance of Devoto.
METHODS:
Documents published by the Istituti Clinici di Perfezionamento, a group of clinics of which the Clinica del Lavoro was part, record the birth and organization of this structure and the presence of a laboratory of chemistry; documents by Devoto and other authors were also retrieved to extrapolate specific information on activities of industrial hygiene and toxicology.
RESULTS:
The Clinica del Lavoro, at the time of its inauguration, included four laboratories: of chemistry, clinical physics, histopathology and bacteriology. The chemistry lab was located on the first floor and was composed of 6 well-lit rooms, modernly equipped with work benches that could accommodate 12 people. In Devoto's view, the chemistry laboratory, supported by that of clinical physics, had to assess the toxicological properties of chemicals commonly found in the workplace and to reveal the mechanisms of induction of damage to humans. In the first 30 years of activity, the Clinica del Lavoro investigated various diseases deriving from exposure to chemical agents, including saturnism, or lead intoxication, mercurialism, phosphorism, benzolism, sulfocarbonism, dust diseases. Several assays were developed and applied to measure toxicants in different biological and environmental mean as evidenced by scientific publications starting from 1920.
CONCLUSION:
In Devoto's view, industrial hygiene and toxicology were essential tools for the research and prevention of occupational diseases since the first years of activity of the Clinica del Lavoro
High-throughput determination of cortisol, cortisone, and melatonin in oral fluid by on-line turbulent flow liquid chromatography interfaced with liquid chromatography/tandem mass spectrometry
No full textRATIONALE:
Cortisol, cortisone, and melatonin (CORTol, CORTone, and MELA, respectively) are hormones related to stress and sleep disorders. Their detection is relevant to epidemiological studies aimed at investigating the effects of circadian cycle disruption. The aim of this study was to develop and evaluate a high-throughput assay for the detection of CORTol, CORTone, and MELA concentrations in non-invasively collected oral fluid samples.
METHODS:
A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method to measure levels of CORTol, CORTone, and MELA in oral fluid samples in the presence of deuterated analogs was optimized and validated. A 50 μL aliquot of oral fluid sample, obtained by centrifugation of a chewed swab, was purified using on-line turbulent flow liquid chromatography. Analytes were then separated using C18 reversed-phase chromatography, subjected to positive ionization using an electrospray source, then quantitated using a triple quadrupole mass detector in the selected reaction monitoring mode.
RESULTS:
Limits of quantification and linear dynamic ranges were found to be 0.55 nmol/L, 5.5 nmol/L, and 0.004 nmol/L, and up to 28 nmol/L, 277 nmol/L, and 0.43 nmol/L for CORTol, CORTone, and MELA, respectively. Inter- and intra-run precisions as relative standard deviation values were <5%, and accuracies were within 95-106% of theoretical concentrations. An evaluation of matrix effects showed that the use of deuterated analogs controlled sources of bias. Furthermore, the total analysis time per sample was 13 min, resulting in a throughput of approximately 100 samples/day.
CONCLUSIONS:
To our knowledge, this is the first automated, high-throughput assay for the simultaneous quantification of CORTol, CORTone, and MELA in oral fluid specimens
High stereoselectivity in the formation of the inter-ribonucleotidic phosphorothioate bond
No full text
An automatic SPME/GCMS assay to measure mono and dihydrohy naphthalenes in human urine
No full textDue to its toxicological relevance and its large presence in working and living environments the need for a specific biological monitoring of naphthalene exposure is recognize. The traditional assay to measure naphthalene metabolites in urine employs time consuming sample preparation, typically performed by liquid-liquid or solid phase extraction, followed by chromatographic analysis. Aim of this work was to set a simple and automatic assay to measure naphthalene mono and dihydroxy metabolites in human urine and to test its applicability in biological monitoring.
Solid phase microextraction (SPME) with on-fiber derivatization was chosen for sample preparation. Optimization was carried on using several fiber coatings and different silylating agents. Stability of the samples was obtained by addition of an antioxidant solution. Separation and detection of the analytes was obtained by GC/MS. The presence of naphthalene metabolites in subjects with different exposures was assayed.
A novel and automatic SMPE GC/MS assay in which 1- and 2-naphthol, and 1,2-, 1,4-, 1,7- and 2,6- dihydroxynaphthols were directly sampled from urine and derivatized by immersion of a PDMS-DVB fiber in silylating agent vapours, was set. Preliminary results obtained analyzing urine samples of non-smoking and smoking not occupationally exposed subjects, and coke oven workers showed levels in the range of those obtained using a traditional approach.
The developed assay is simple, and time and reagent saving. It opens interesting perspectives to enlarging biomonitoring of naphthalene exposure in human
Modificazioni epigenetiche nell'esposizione a basse dosi di benzene
No full textDNA methylation, mitochondrial DNA copy number and telomeres shortening are cellular modifications associated with an increasing number of tumors, cardiovascular and aging diseases. In our studies these modifications were evaluated in subjects occupationally exposed to low levels of benzene and in the general population. In peripheral blood lymphocytes a decrease of DNA methylation with the increase of personal benzene exposure was found, both in Alu and LINE-1 repetitive elements, and in the global DNA. Telomere length shortening in subjects exposed to traffic exhausts and an increase in mitochondrial DNA copy number correlated to benzene exposure was also found. DNA methylation measured in specimen repeats collected at intervals of 8 years decreased more markedly in exposed subjects than in controls. Our studies highlighted the association of epigenetic modifications of DNA with low benzene exposure
Determination of terbuthylazine and desethylterbuthylazine in human urine and hair samples by eletrospray ionization-liquid chromatography/triple quadrupole mass spectrometry
No full textTerbuthylazine (TBA) is a widely applied herbicide and an environmental contaminant. Following its use, humans, such as agricultural workers and rural residents, may be exposed. An isotope-dilution liquid chromatography coupled to electrospray-tandem mass spectrometry method for the determination of TBA, and its metabolite desethylterbuthylazine (DET) in human urine and hair was developed and validated. Under the optimised conditions, analytes were extracted from urine using a solid phase cartridge or from hair by sonication in methanol. Analytes were separated using a C18 reversed-phase chromatographic column and quantified, after positive ionization using a heated electrospray source, by a triple quadrupole mass detector in the selected reaction monitoring mode. Validation showed linear dynamic ranges up to 100 μg/L or 5.00 ng/mg hair, inter- and intra-run precisions <7%, and accuracies within 12% of spiked concentrations. Limits of quantification were 0.25 μg/L in urine and 0.01 ng/mg hair for both TBA and DET. Matrix effect evaluation showed that the isotope dilution approach allowed for the control of bias sources. TBA and DET were determined in specimens of agriculture workers exposed to TBA using the validated method. Hair samples contained TBA levels in the low nanogram per milligram range, and urine samples contained DET levels in the low microgram per liter range. Conversely, TBA levels in urine samples and DET levels in hair samples were always below the limit of quantification
Idrocarburi policiclici aromatici cancerogeni urinari : confronto tra soggetti con e senza esposizione occupazionale
No full textFast liquid chromatographic determination of urinary trans,trans-muconic acid
No full texttrans, trans-Muconic acid (1,3-butadiene-1, 4-dicarboxylic acid, MA), a minor urinary metabolite of benzene exposure, was determined, after clean-up by solid-phase anion-exchange chromatography, by reversed-phase HPLC on a C18 column (5 x 0.46 cm I.D., 3 microns particle size), using formic acid-tetrahydrofuran-water (14:17:969) as mobile phase and UV detection at 263 nm. The recovery of MA from spiked urine was > 95% in the 50-500 microgram/l range; the quantification limit was 6 micrograms/l; day-to-day precision, at 300 micrograms/l, was C.V. = 9.2%; the run time was less than 10 min. Urinary MA excretion was measured in two spot urine samples of 131 benzene environmentally exposed subjects: midday values obtained in non-smokers (mean +/- S.D. = 77 +/- 54 micrograms/l, n = 82) were statistically different from those of smokers (169 +/- 85 micrograms/l, n = 30) (P < 0.0001); each group showed a statistically significant increase between MA excretion in midday over morning samples. Moreover, in subjects grouped according to tobacco-smoke exposure level, median values of MA were positively associated with and increased with daily smoking habits
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